Pioneer CDJs are a line of digital music players specifically designed for DJing. Originally created to play music from CDs, modern CDJs can also play digital music files from USB drives and SD cards. Typically, DJs use at least two CDJs connected to a DJ mixer to create seamless transitions and mixes. These players are equipped with jog wheels and pitch faders, allowing DJs to manipulate digital music similarly to using vinyl records on turntables. Over the years, Pioneer CDJs have become an industry standard in clubs and DJ booths worldwide, known for their reliability and advanced features like looping and beat analysis.